Comparison of Environmental DNA and SCUBA Diving Methods to Survey Keystone Rockfish Species on the Central Coast of British Columbia, Canada

Within this work we address the relevance of integrating molecular techniques; particularly environmental DNA (eDNA) methods into biological monitoring programs. We focused on the Sebastes genus; a group of important fish in the Pacific Northwest of North America. They are particularly interesting from an evolutionary standpoint due to a high degree of interspecific sequence conservation paired with a high degree of intraspecific sequence variability. We used a novel whole mitochondrial genome approach to overcome these challenges and create successful targeted qPCR eDNA assays for species of particular importance. We also used a metabarcoding approach to compare molecular community diversity estimates with those made by conventional diving methods. We found that molecular techniques were highly sensitive and could detect more species overall. However, both molecular and conventional methods have their strengths. In terms of species and habitat protection, using multiple techniques together will be most impactful.

本研究探讨了将分子技术——尤其是环境DNA（environmental DNA, eDNA）方法——整合入生物监测项目的重要意义。研究聚焦于平鲉属（Sebastes）：该类群是北美西北太平洋海域的重要经济鱼类类群，从进化生物学视角来看极具研究价值，因其兼具极高的种间序列保守性与显著的种内序列变异度。为攻克这一研究难题，本研究采用了全新的全线粒体基因组分析方法，成功针对重点保护物种开发出靶向实时定量聚合酶链式反应（quantitative polymerase chain reaction, qPCR）环境DNA检测体系。此外，本研究还运用了元条形码（metabarcoding）技术，将分子群落多样性评估结果与传统潜水调查法所得结果进行对比分析。研究结果显示，分子技术灵敏度极佳，整体可检测到更多物种；但分子与传统调查方法各有其优势与适用场景。就物种与栖息地保护而言，联合使用多种监测技术将实现最佳的保护成效。